Prince William has been joined by a host of stars to celebrate one of the world's most famous cancer hospitals.

Benedict Cumberbatch, Emma Watson and Helena Bonham Carter were among those invited to the black-tie event at Windsor Castle honouring the Royal Marsden, which was founded in 1851.

Another guest was designer Ralph Lauren, whose donation has helped fund a new breast cancer research centre which bears his name.

The Duke of Cambridge is the hospital's president, following in the footsteps of his mother Diana, Princess of Wales.

He chatted to many of the star guests, including supermodel Kate Moss, who asked about his wife the Duchess of Cambridge, who was not at the event.

William, who spent two days on work experience at the hospital in 2005, told guests: "I am exceptionally proud to be president of the Royal Marsden, an incredible hospital and a world-class cancer centre carrying out ground-breaking work, influencing the treatment of cancer both nationally and internationally.

"I have experienced this brilliant work first hand during several visits to the Royal Marsden.

"Only last year, I visited the Chelsea hospital and saw for myself some of the complex and pioneering surgery that takes place on a daily basis."

He added: "The Royal Marsden Cancer Charity is a crucial part of the life-saving work of the hospital. It is the charity that helps to provide the best state-of-the-art facilities for modern cancer care."